Pressure Matrix

PRESSURE
MATRIXExpressive synthesizer · 10 voices

Breath Pad

Osc + SVF

OCTAVEC3

VOICES0 / 10

PRESS0.00

TIMBRE0.50

BEND+0.00

MIDIoff

Macros

Keys

Press ↑ Timbre →

Laptop keys

Click anywhere on the page once so it gets your keystrokes, then play.

Z–/ Q–]: Notes. Bottom row is the low octave, top row the next one up. Number keys are the sharps.
Shift + note: Hard strike. Without Shift, notes use the Strike knob.
Space (hold): Press. Pushes every held note into the deep part of the key, like leaning on an Osmose key after it bottoms out.
Touch plate: Press and timbre. Move a finger on the trackpad over it. Height is press, left to right is timbre.
← → (hold): Sideways pitch. Bends the newest note down or up two semitones, like rocking the key.
↑ ↓: Octave. Esc stops all sound.
Mouse on a key: One note, full control. Click lower on the key for a harder strike, drag down to press, drag sideways to bend.
Knobs: Drag up or down. Hold Shift for fine moves, double-click to reset.

MIDI keyboard

Plug in a USB MIDI keyboard, then press MIDI on the panel. The notes below are for a Behringer Swing; other keyboards with aftertouch map the same way.

Keys: Notes and strike. How hard you hit sets the strike, the way Osmose strike does.
Aftertouch: Press. Push down on a held key. This is the closest the Swing gets to the Osmose's deep key travel.
Pitch strip: Bend for every note on that channel.
Mod strip: Timbre by default. Switch it to press below if aftertouch feels too stiff.
Sustain jack: Sustain pedal holds notes.
Arp / sequencer: The Swing's arpeggiator and sequencer play the synth too.

Mod strip controls Bend range

MIDI keyboards can't connect inside the claude.ai viewer. To play with one, open nokill-pedal-co.github.io/pressure-matrix in Chrome or Edge.

What the real engine does, and what this does instead

Inside the Osmose

The sound engine is the EaganMatrix: a modular digital synth designed by Edmund Eagan, running on a DSP engine by Lippold Haken. It is the same engine as in the Haken Continuum and ContinuuMini.
In the Osmose it runs on six SHARC DSP chips and plays up to 24 notes, often as 12 stereo voices. There is no sample playback.
You patch it on a grid. Key gestures enter the matrix and pass through small letter-named formulas that scale, limit or combine them before they reach the synth blocks.
The blocks are five oscillators or waveshapers plus noise, five multimode filters, two filter banks of 8 or 48 filters, delay lines for chorus, flanging and physical modelling, shape generators, a convolution module, and a "recirculator" for delays and reverbs.
Haken's tutorials name the bank types: BiqBank, BiqGraph, BiqMouth, SineBank, Sine Spray, WaveBank, the Additive and Kinetic banks, and the Harmonic and Modal Manipulators.
Each key senses three things. Strike comes from the key's travel over time, which carries more than plain velocity. Press is extra travel past the normal key bottom. Pitch comes from rocking the key sideways. There is no front-to-back sensing.
The Osmose ships with more than 500 factory presets, each with six macros. You edit them in the Haken Editor, which runs in Cycling '74 Max.

What this page does

The EaganMatrix is closed. Its presets are patches for Haken's DSP, not code anyone can run, so this can't be a clone. It rebuilds the same synthesis families in an AudioWorklet and wires them to the same three gestures.
The 27 presets here are originals, sorted by sound the way the Osmose sorts its library. None of them are copies of Osmose factory sounds. A MIDI program change picks a preset by number.
Every note gets its own strike, press, timbre and pitch, the way MPE works. An MPE controller plugged in over MIDI gets per-note bend and press too.
Laptop keys only know up or down. Strike comes from Shift or the Strike knob, and press comes from Space, the touch plate or a mouse drag.
Most laptop keyboards can only register 3 to 6 keys at once. Some chords will drop notes. That is the keyboard hardware, and the synth can't fix it. A MIDI keyboard doesn't have that limit.

Engine here	EaganMatrix relative	Press does
Osc + SVF	Oscillators into multimode filters	Opens the filter, swells the level, adds vibrato
Sine bank	SineBank / Additive	Flattens the spectral tilt so upper partials come in
Formant bank	BiqBank-style resonant filter bank	Opens the vowel and adds breath
Modal	Resonator banks / Modal Manipulator	Bows or rubs the resonators so they sustain
Bowed string	Delay-line physical model	Bow speed. Timbre sets bow pressure.
Plucked string	Delay-line physical model	Longer ring, and an e-bow drive on some patches

Sources: Sound On Sound, Osmose review · Loopop, Slim Continuum tutorial · Perfect Circuit, Osmose review · Haken Audio, EaganMatrix Module · Adorama, Behringer Swing specs. Not affiliated with Expressive E, Haken Audio or Behringer.